Changes in Reference Evapotranspiration and Its Contributing Factors in Jiangsu, a Major Economic and Agricultural Province of Eastern China

Reference evapotranspiration (ETref) is a key parameter of hydro-meteorological studies as well as water resource planning. In this study, we adopted the Penman–Monteith FAO 56 model to estimate ETref and through the differential equation and detrending method to determine sensitivities and the contributions of four meteorological parameters to ETref based on daily weather data from 60 stations of Jiangsu province during 1961–2015. Results reveal that ETref and its trends in the three sub-regions of the Jiangsu province had a significant spatial heterogeneity. A significant decreasing tendency of ETref (p < 0.001) was observed in the Huaibei region, while a slightly increasing tendency was identified in the Jianghuai and Sunan regions. These changes of ETref were caused by a significant increasing…